Research On Technological Parameters And Keyequipment Of Microcellular Foam During Injection Moulding

In recent years, the prices of plastic raw materials have been rising because of theenergy shortage especially oil, and how to save materials in the premise of ensuring theperformances of the products, is a hot issue at present. Microcellular Foam duringInjection moulding is a new technology to research and develop. It effectivelyovercomes the shortcomings of the traditional foam process, so this technology iswidely used at home and abroad.Many researches show that the performances of microcellular injection productsgreatly depends on the generated micro porous shapes—the hole diameter and density,so how to control the micro porous shapes in order to ensure the quality of microcellularinjection products is one of the research directions in this field. In this paper in order tocontrol the micro porous shapes of the injection samples to improve the quality of thesamples, microcellular foam and injection technological conditions and the keyequipments for research are made as the objects. This article mainly includes:(1) Based on the mechanism analysis of microcellular foam and injection process,the mathematics model of melt filling and flowing is established. And taking the bubblegrowing up as the key research object, by introducing reasonable hypothesis andsimplifies, the bubble cell model is used for the mathematics model of the bubblegrowing up on the basis of the basic equations of hydrodynamic. In the microcellularfoam and injection process, melt filling and flowing condition is researched byMoldflow simulation experiment to take a thin-walled part as the research object. Itmainly includes the filling time, the injection pressure, the front temperature of meltflowing, the melt orientation and the warping deformation analysis.(2) In the microcellular foam and injection process, melt filling and flowingcondition is researched by Moldflow simulation experiment to take a thin-walled part as the research object. It mainly includes the filling time, the injection pressure, the fronttemperature of melt flowing, the melt orientation and the warping deformation analysis.(3) Through the analysis and comparison, select the process parameters influencingaverage diameters of bubble holes as the research objects. First, the average diametersof bubble holes are observed in different positions of the mold flow direction by thesingle experiment, then by the single factor experiment the influence law of the selectedprocess parameters on the microporous form is researched and the accuracy of theoptimum process parameters of validation simulation method is tested through theorthogonal experiment table.(4) The influence of the geometric parameters and structure of the screw on the melt mixingeffect and melt temperature uniformity is analyzed; And based on screw geometric parametersoptimization through the genetic algorithm, the microcellular foam and injection molding specializedscrew is designed, and a stable back pressure hydraulic system of the screw is established; a simplesimulation analysis of the specialized screw on the mixed effect is made through ProE/Mechanicafunction module.At the same time on the basis of the original simple equipment, the supercriticalfluid system is established based on the electrical control.The study show that, and the optimization of the process parameters and the key equipment ofmicrocellular foam and injection process help improve the microporous form of micro porousfoaming products,and effectively improve micro porous foaming product quality.